Engineering design work has now commenced for the construction of a £600m
offshore gas storage facility
in the Irish Sea.
The Gateway gas storage project will be built in salt caverns approximately 750m
beneath the surface of the seabed
and located 15 miles offshore, south west
of Barrow-in-Furness.
19 man-made underground storage caverns will be created by a solution mining
process known as leaching.
This involves cycling large amounts of seawater
through a salt formation deep beneath the seabed.
A single leg offshore structure
(‘monopod’)
will be installed above each of the 19
caverns. The monopods will be used to
accommodate equipment in support of
the leaching process during construction
(pumps, motors, control systems and
ancillary equipment). Two leaching strings
(pipe-in-pipe) will be hung from the deck
of the offshore structure to facilitate
seawater injection and brine discharge.
The seawater dissolves the salt, leaving
an empty space (‘cavern’) in the strata.
The brine resulting from this process is
brought back to the surface and
discharged into the sea via a disperser
unit.
After construction
the monopods will
remain in place and act as the wellhead
for the injection and release of the gas. |
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The facility will be connected via a new pipeline routed from the storage area to
the shore, across Walney Island and Piel Channel, to a site adjacent to the
existing North and South Morecambe gas terminals at Barrow.
AMEC, Parsons Brinckerhoff and Senergy have been appointed by Gateway
Storage Company to undertake the front-end engineering design (FEED) work
AMEC’s work will include offshore installations, pipelines, the onshore
compression station at the Morecambe terminals and the connections into the
National Grid. Parsons Brinckerhoff will advise Gateway on the salt cavern
design and construction, and Senergy’s work will concentrate on the offshore
infrastructure, installation, logistics and well designs. The project team will be
based in Aberdeen.
Design work will take around 12 months, with construction expected to start
at the end of this year, with a completion date
of 2014.
With a storage capacity of 1.5bn cubic metres, Gateway will hold sufficient gas
to supply the entire UK for 5 days.
Project Website:
www.gatewaystorage.co.uk
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